Heat a 4-quart sauce pot over medium high heat. Add olive oil and onions, sauté until translucent, about 8 minutes. Add garlic and sauté until fragrant, about 2 minutes.

Add tomatoes, tomato paste, sugar, molasses and cider vinegar. Bring to a slow boil, lower to a simmer and using a spoon crush the whole tomatoes. Add remaining ingredients and continue to simmer, uncovered for 45–55 minutes, stirring occasionally, until very thick. Make sure to keep an eye on it and stir it to keep it from scorching.

Use an immersion blender to puree the ketchup. If you don’t have an immersion blender, transfer it carefully to a blender or food processor and process until smooth. (Optional: Strain through a fine mesh strainer.) Chill in refrigerator for at least 2 hours. The ketchup will continue to develop flavor and thicken.